Somoleptus alajuelae, Irmler, 2024

Irmler, Ulrich, 2024, Additions to Neotropical species of the genera Lithocharodes Sharp, 1881 and Somoleptus Sharp, 1881 (Coleoptera, Staphylinidae), Contributions to Entomology 74 (1), pp. 13-34 : 13

Somoleptus alajuelae sp. nov.

Figs 11a-d , 20E

Material examined.

Holotype: COSTA RICA male; Alajuela; San Ramon ; 5 km W; 1200 m elevation; 1-31 Dec 1997; P. Hanson leg.; KNHM CR1HAN92-97 14.

Paratypes: COSTA RICA 1 male; Puntarenas; Monte Verde ; 1400 m elevation; 14 May 1989; J. Ashe, R. Brooks, R. Leschen leg.; Snow Entomol. Mus. Expedition KNHM #188 ; 1 male; San José; Zuruqui de Moravia ; 1600 m elevation; April-May 1993; P. Hanson leg.; KNHM ; 1 male; Guanacaste; Cacao Biological Station ; 10°56'N, 85°27'W; 1000 m elevation; tree-fall litter; 5 May 1995; J.S. Ashe leg.; KNHM .

Diagnosis.

The structure of the aedeagus of S. alajuelae does not fit to any of the known Somoleptus groups. The processes at the aedeagal orifice are neither brush-like nor translocated into the inner part. Thus, the overall structure of the aedeagus is unique within the Neotropical Somoleptus species. Together with Somoleptus paramocola sp. nov., it forms a new sub-group of the S. alticola -group. According to the total size and length of eyes, S. alajuelae resembles S. subtilis (Erichson, 1839). Even the shape of the aedeagus and the unique shape of the apical processes are vaguely similar to S. subtilis . In contrast to S. subtilis , S. alajuelae is totally black. The differences to S. paramocola are listed there.

Description.

Length: 3.69 mm; Colouration: completely black; antennae light brown; legs even lighter brown.

Head: 0.67 mm long, 0.51 mm wide; eyes prominent; large; PS:E ratio 2.6; sides slightly divergent; without posterior angles; posterior part widely rounded; nearly semi-circular; inter-antennal furrows divergent; reaching mid-length of eyes; setiferous punctation deep and dense; between eyes partly coriaceous; narrow mid-line between eyes and wide mid-spot on disc impunctate; on average, interstices between punctures of hind-head half as wide as diameter of punctures; surface without microsculpture; polished; antennae with first antennomere elongate; shorter than half-length of head; second and third antennomere conical; combined half as long as first antennomere; following antennomeres transverse; apically increasing in width. Pronotum: 0.79 mm long, 0.48 mm wide; widest at anterior third; posteriorly slightly divergent; posterior angles sub-rectangular; setiferous punctation irregular; anteriorly denser than posteriorly; in posterior half, interstices at least as wide as diameter of punctures; wide mid-line impunctate. Elytra: 0.72 mm long, 0.63 mm wide; humeral angles obtuse; sides parallel; posterior angles sub-rectangular; posterior margin slightly retreated to suture; setiferous punctation irregular; in apical part, extremely deep and dense; nearly coriaceous; in posterior part sparser; on average, interstices half as wide as diameter of punctures; surface without microsculpture; polished. Abdomen finely and sparsely punctate; surface without microsculpture; polished; sternite VII of male with slightly convex posterior margin; tergite VII of male with triangularly prominent posterior margin; meso-tibia with 5, meta-tibia with 3 ctenidia. Aedeagus nearly circular; dorsal plate covering nearly total central lobe; apical orifice large; with pair of non-brushed prominences formed like cow horns; C:A ratio 0.3; parameres slightly projecting horn-like processes; bilobed; inner lobe with wide base; abruptly narrowed apically; hook-like top; at apex with several long setae and few elongate sensillae; outer lobe transparent; narrow; slightly curved.

Etymology.

The species name is derived from the Costa Rican Province Alajuela.

Geography.

Western Costa Rica.

Ecology.

Forest floor between 1000 and 1600 m elevation from December to May.

Figures

Figure 20. A. Fore-body of Lithocharodes lituratus; B. L. montanus; C. L. parallelus; D. L. zamorae; E. Somoleptus alajuelae; F. S. curtioculatus. Scale bars: 0.5 mm.

Figures 9 - 12. 9. Lithocharodes parallelus; 10. L. zamorae; 11. Somoleptus alajuelae; 12. S. curtioculatus. a. Aedeagus; b. Paramere; c. Sternite VII; d. Tergite VII. Scale bars: 0.5 mm (a, c, d); 0.1 mm (b).